Automatic electric metal-working machine.



No. 821,061. PATENTED MAY 22, 1906. A. F. RIETZEL & G. E. BARSTOW.AUTOMATIC ELECTRIC METAL WORKING MACHINE.

APPLICATION FILED DEC. 5. 1904.

8 SHEETS-SHEET l.

INVE NTQRS No. 821,061. r PATENTED MAY 22, 1906. A. P. RIETZEL & G. E.BARSTOW. AUTOMATIC ELECTRIC METAL WORKING MACHINE APPLICATION FILED DEC.5. 1904.

8 SHEETSSHEET 2.

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J-\ A TTOR/VEYS No. 821,061. PATEN-TED MAY 22, 1906.

A. F. RIETZEL & e. E. BARSTOW.

AUTOMATIC ELECTRIC METAL WORKING MACHINE. APPLICATION FILED DEC. 5,1904.

a SHEETS-SHEET s.

Arm/mus No. 821,061. PATENTED MAY 22, 1906. A. F. RIETZEL & G. E.BARSTOW. AUTOMATIC ELECTRIC METAL WORKING MACHINE.

APPLIOATION IILBD I)EO. 5. 1904.

8 SHEETSSHBET 4 ATTORNEYS No. 821,061. A PATENTED MAY 22, 1906.

' A. F. RIBTZEL & G. E. BARSTOW.

AUTOMATIC ELECTRIC METAL WORKING MACHINE.

APPLIOATION FILED DEC. 5. 1904.

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7 77 GEQ //'f 5 w 78 ATTORNEYS No. 821,061. PATENTED MAY 22, 1906.

A A. P. RIETZBL & G. E. BARSTOW.

AUTOMATIC ELECTRIC METAL WORKING MACHINE.

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APPLIOATIOH FILED DBO. 5. 1904.

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PATENTED MAY 22, 1906. A. F. RIETZEL.& G. E. BARSTOW. AUTOMATIC ELECTRICMETAL WORKING MACHINE.

APPLICATION FILED DEC. 5, 1904.

8 SHEETS-SHEET 7.

WITNESSES.

No. 821,061. PATENTED MAY 22, 1906. A. F. RIETZEL & G. E. BARSTOW.AUTOMATIC ELECTRIC METAL WORKING MACHINE.

APPLICATION FILED DEC. 5. 1904.

8 SHEETSSHEET 8.

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ATTORNEYS .No. 821,061. I

Z UNITED STATES- PATENT OFFICE. I

. ADOLPH F. R1ETZEL AND GEORGEIE. BOAROSTOIW, OF LYNN, MASSACHU- SIETTS.ASSIGNORS TO THOMSON ELECTRIC WELDING COMPANY, or

LYNN, MASSACHUSETTS,"'A CORPORATION OF MAINE. I

AUTOMATIC E Ec'rmo METAL-WO ING MACHINE.

To all whonf it mmy concern: I Be it known that we, ADoLPH F. RIETZELand GEORGE E. BARSTOW, citizens of the United States, and residents ofLynn, in the county of Essex and State of Massachusetts,

(whose *POSl'FOffiCB address is Lynn, Massa chusetts,') have inventedcertainnew' and useful Improvements in Automatic Electric Metal-WorkingMachines, of which the fol lowing is a specification;

- Our invention relates to an electric metal-' working ap aratus whereinthe work is heated to the esire d extent by the passage of electriccurrents through the section of metal to be welded, forged, or otherwiseoperated upon. I

The main object of our invention is to pro vide amachine which shall beautomatic in all its actions and in which nothing shall be required ofthe attendant save to place the work in the machine and to remove'it therefrom.

While we have described our invention as carried outin a machine inwhich a forging tool or implement is used upon the heated section ofwork after it has been rendered sufficiently plastic, it will 'bereadily understood that we do not limit ourselves to the use of suchtool, since the principle of opration of the parts of our machinewouldbe ap-' shoul plicable to a machine in which no forgingtool should beemployed. It will be also obvious from the subjoined description thatthe principles of operation of our invention could sumes a plasticcondition through-the heating effect of theelectric current.

' Another part of our invention relates to the specialdevices forcontrolling the motions of. a master shaft which is provided with meansfor bringing the various parts of the machine into operation in therequired sequence. This part of our invention consists, among otherthings, broadly, in making the restarting of the master-shaft after ithas been brought to rest automatically through the yielding of the workdependent upon the Specification of Letters Patent. ,g pii ati m aDecember 5,1904. 'sriti'nazassez,

-'or other power.

Patented. maize, 1906.

" operation of the forging devices which them selves are brought intoaction automatically 5 5 by the movement of the parts which arepermitted to move through yielding. of the heated section of work.

Our invention relates, further, to that classof electric metal-Workingapparatus 6o wherein pressure is applied to the heated section of workfor the purpose of effecting the Weld or for other purpose by means ofspring Iuption of the heated section by too sudden application of thecompressing force; to which end theinvention consistsin theapplicationof a pounteracting s ring or other retarding I means ada tedto de ay or slow down the operation of t e device by which the weldingor other pressure is applied, as hereinafter more particularly setforth. I

Our invention consists also in special means for applying and regulatingthe retard- 7 5 ing effect; I

Our invention consists also in the special combinations of devices andmechanisms hereinafter described "and then recited in the claims; and,further, in special constructions and combi tions of the mechanisms usedfor control ing the flow of heating-current and for starting andstopping the mastershaft and the forgin too all of which will bedescribed, and -t en pointed out more specificallyin the claims Ourinvention is especially useful for welding-machines em loyed for weldingthin stock, such as ba e-ties or hoops, but is applicable likewise tomachines designed for other Work.

In the accompanying drawings, Figure 1 is a front elevation of a machineembodying our invention. Fig. 2 is a front elevation of the upperportion of the machine, the press being 5 removed. Fig. 3 is' a sideelevation of the machine. Fig. 4 is a plan of the automatic switch orcurrent controller that controls the fiow of current through the work.Fig.

5 is a side elevation of one arm ofthe current- I00 controller'andthetrip ing mechanism. Fig. 6 is an enlarged side e evationof one arm ofthe current-controller in open position. Fig. 7 is a plan of one of thework-holders. Fig. 8 is a side elevation of the same; side elevationshowing the train-of gearing The object of this part of I our inventionis particularly to prevent'dis- 65 Fig. 9 is a between the power-wheeland the mastershaft, the intervening mechanism being removed. Fig. is anelevation of the mechanism for starting the forging-tool automaticallywhen the work-holding slide is permitted to move forward by thesoftening of the work. Fig. 11 is a plan of a portion of said mechanism.Fig. 12 is a front elevation of part of the mechanism for stopping themaster-shaft. Fig. 13 is a plan of the same in a position where themaster-shaft has been thrown out of gear. Fig. 14 is the same as Fig.13, except that the master-shaft is revolving. Fig. 15 is a verticalsection and partial elevation of the press or forging mechanism. Fig. 16is a modification of the form of the die or tool. Fig. 17 is a sideelevation of part of the device used to stop the revolution of themaster-shaft, parts having been broken away. Fig. 18 is a view'of thesame at a different stage in the operation. Fig. 19 is a view of thesame at a still further stage in the operation. -Fig. 20 is a diagram ofthe electric circuits of the machine. Fig.

'21 is an elevation of the device for releasing the movable work-holderand allowing it to move forward. Fig. 22 is a modification in the formof the device for starting the press or forging mechanism. Fig. 23 is amodifica tion of Fig. 22.

1 is the main table or platform of the machine and is supported by thelegs 2. Superposed on the table 1 is the framework, carrying theoperating mechanisms, as will be presently described.

3 3 indicate work-holding slides or carriers consisting of slidingblocks or platens,

consisting of suitably-formed castings, upon which are mountedwork-holders comprising clamping devices for clamping the work. These,as usual in the art, may be in electrical connection with any suitablesource of heating-current in order to supply current to the work, andone of them is suitably mounted and guided so as to permit it to bemoved toward and away fromthe opposite platen. 3 is the movable platenwhich works in suitable guides 4, mounted upon, but insulated from, thetable 1. Current may be supplied to the work through the platens orblocks 3 3, which for that purpose may beterminal blocks of thesecondary of a transformer which may be constructed as described inUnited States Letters Patent issued to A. F.

.Rietzel, No. 649,179, dated May 8, 1900.

The flexible terminals 5 5 of said secondary are connected to the blocksor platens 3 3.

The principal portion 6 of the secondary is aother suitable manner.Mounted on the platens or blocks 3 3 are clamp bodies or frames 8 8 andcom osed, preferably, of an extension of the blocl s or platens 3 3.Each clamp-body carries a pair of clamping-jaws The upper jaw 9, whichmay be of the construction in the patent to A. F. Rietzel, No. 719,508,dated February 3, 1903, or of any other desired construction, is mountedon a lever 10 and is forced toward the opposite jaw by the action of aspring 11 or other device adapted to clamp the work to be heated. Theclamp-lever 10 on the sliding or movable block 3 is acted upon by a cam12, secured to an intermittently-revolving shaft 13 and adapted toengage with a friction-roller 14 on the lever 10. A similar cam 12operates on the lever 10 for the clamping-jaw on the opposite orfixedblock or platen 3. This shaft 13 is hereinafter termed an1aster-shaftand besides carrying means for controlling the movements of thework-holding slide and the operation of the clamping devices for thework also carries means whereby the flow of heating-current in the workmay be established and means whereby the shaft may be broughttemporarily to rest at a certain stage of the operation. These meansconsist, preferably, of suitable cams and coacting parts.

As shown in Fig. 8, the cams 12 12 may be so formed that the clamp-leverin the stationary platen will be operated by the cam to free the workslightly before the lever on the movable or reciprocating platen. Thework is clamped by the action of the springs 1 1 so long as the leversare free from engagement by the cams. The manner in which the shaft 13is started and stopped will be presently described. Shaft 13 is mountedin bearings 15 on standards 16, fastened in any suitable manner to thetop of the table. The lower jaws 9' are held against the face of aprojection 17 from the clamp-body by means of a bolt 18, passing throughan enlarged openin in the projection, so as to permit vertica adjustmentof the clamp-jaw by means of adjusting-screw 19. By loosening theclampbolt 18 and turning screw 19 the jaw may be adjusted vertically forwear of its biting-face or for other purposes and when adjusted may befixed in position by the bolt 18. Each jaw 9" works in suitable guidesformed in the face of the projection 17. The platen 3 is forced towardthe opposite platen or block by any suitable nieansas, or instance, bymeans of the spring 20, which enters a socket in the rear of the block.The screw 21, mounted in the post 22, serves to adjust the compressionof the spring 20 andthe force applied by the spring to the platen andthrough the same to the heated section of work between the two sets ofclamping devices.

In the operation of welding or otherwise tion of the compressing forcethat is used to working thin stock the heated section of the work whenit is in a highly-plastic condition would be disrupted by a too suddenapplicamove the one block or platen, with its clamping devices, towardthe other. This is aditt'r' culty which is met with particularly in the(operation of automatic machines wherein a spring is employed to exertthe usual Welding or upsetting pressure. and .is permitted .to operateas soon as the work becomes plastic by the heating effect of thecurrent, thus permitting the blocker slide to ,Which the spring isapplied to move forward. To avoid this trouble, we propose to combinewith; the s ring some means for retardingthe'action thereof and theconsequent. movement'of the parts as the work softens. lSuch retardingappliance may conveniently consist of a counteracting or opposingspring,.which, if

I it. beapplied so as toeop' ose the action of the s ring20, during thew ole movement of the' s ide.3 shouldbeweaker than the spring 20. Thecounteracting or retarding s ring is here shown as a coil-s ring 23,suita 1y con-' nected to .the slide 3 t ough the rod 24, one end ofwhich is pinned to alug beneath the slide, while its opposite end iscoupled to one arm of a lever 26, the'other arm of which engages spring23'and compresses the same between block 27, carried on 'the end flofthe'signe lever and the end-of an adjustin -screw 28, which is' mount'ed'on a suitab e arm or bracket 29, fastened to the flange-30, .dependingfrom table 1'. This screw28 serves to take up the space between-the endvof the spring and the bracket when it is necessary to narrow thedistance between the slides 3 3' forthe purpose of welding narrow-Widthstock. (In that case the screw isset upagainst spring 23, but not so asto put the spring under tension, as the spring is not deto act until theslide begins to move. On the other hand, if it be desired to weld widerstock it is necessary -to increase the space betweenthe' slides, whichwould put e spring under pressure while the slide 3-. is at rest, 'toavoid which the adjusting-screw 28 is set back. The lever 26 isfulcrumed on a pin 31, whose vertical positionisadjustable for thepurpose of varying the relative length 'ofthe' arms connected to the rod24 and to the spring 23, thereby permitting the retard ing efiect .ofthe spring 23 upon the action of the spring 20 to be adjusted fordifferent sizes of work. I e

The slide 3 is retracted by the action of the cam 32 on theintermittently-rotating shaft 13 or other appliance timed to act in thecycle of operatlons, as-.will be described under the general operation.This cam is formed in the face of a disk which is engaged by one arm ofa lever 33"; the other arm of which acts on the slide 3 in any suitableway-as, for instance, by impinging againstthe in t

a projection on the rod 24, which projection comprises, preferably, anadjustable screw 34, by adjusting which the extent to which the slide 3is retracted may be varied for different sizes of work. Theintermittently-r0 tating shaft 13 also carries two cams or lugs 35 and.35, which act upon the two members of the circuit-controller, which willbe de scribed-later on. Another cam 36 on said shaft isemployed't oautomatically reset a part of the devices which automatically couple thepower to the press or hammer mechanism when the slide 3 hasbeen'perniitted to move forward by the work assuming plastic condition.v An additional cam'37 upon said shaft is used in connection with thedevices which couple and uncouplefth shaft 13 from the power to secureintermittent-rotation thereof. a 1

We will first describe the manner in which the press or hammer isautomatically brought into play and then describe the means for seblock40, secured to and preferably insulated from the top of the table, asshown more clearly in Figs. 1 and 3. The upper die or prejss3'8 isfastened to a block 41, which is adjustably mounted a head 42, workingin guldes 43, which are bolted to posts 44, rlslng from the castingwhich has the-guides 4 for the slide 31. The posts are fastened by bolts45, passing up through the edge "of the table.

Thehead 42, which carries the. upper press or die 38,-is reciprocated bypitman 46, pivotally connectedwith the head 42aat the rear thereof, asshown in Fig. 15, and actuated by a crank or eccentric 47 on the shaft48, which turns in bearings at the top of the casting or frame carryingthe guides for the press-head 42: Shaft48 normally stands at rest.. The

"power-wheel 49, driven in any suitable man;

ner, normally runs freely on the end of said shaft, and its hub carriesthe gear-wheel 50,

gearing with wheel 51, from which motion is imparted to the-cam.-shaft-. 13, as will be pres ently described. The power-wheel 1scoupled to shaft 48 for the purpose of operat ng the press by means of aclutch or couphng device connected to a controlling arm or lever 52. 4 jg The form of. clutch employed b us 1s not material torour invention.That s own comprises a coupling pin or key 53, adapted to rock or turnin a groove formed in the shaft 148 and cut away or mutilated at itsedge opposite a-recess on the inside of the hub 54 of ower-wheel, sothat when the parts are l ie position shown in Fig. 10 the hub of thepower-wheel may rotate 11 eely without being coupled to the shaft. t v

A spring 55, attached, at one end to a stud 56, projecting from a disk57, fastened to the shaft and attached. at its other end to the bent armor lever 52, which is carried by the clutch-key, tends normally to turnthe key or pin so as to bring the unmutilated portion thereof into therecess on the inside of the hub, as shown in Fig. 3. A stop-pin 56, set

- in the side of the disk 57, limits the movement of theclutch-controlling arm when actuated by the spring 55. When so turned,

1 the hub and shaft are locked together, and

the said shaft rotates, carrying-with it the controlling arm or lever52. The key is normally restrained from turning by the dog 58,

Figs. 10 and 11, which is mounted in aimed armiir bracket 59, extendingfrom frame 60, which is attached to or forms a vertical extension of oneof the standards 16. The dog 58 is operated by arod 61,having a pin 62,

' which plays betweenthe arms of a yoke carried by the dog. Said rod 61reciprocates in.

bearings in the frame60. A spring 63 acts on the rod in a direction tooperate the dog 58 and release the arm 52, so that the clutch ,pi'n orkey may turn and couple the powerwheel to the shaft. The spring is,however, normally restrained from so doing by a pivoted catch or detent64, held in engagement with a shoulder 65 on the rod by means of aspring 66. The catch 64 is mounted in a bracket 67, projecting fromframe 60, and is operated by a 0g 68, pivoted in a plate secured to theend of a rod 69. Applied to the rod is a spring 70, which is permittedto force the rod 69downward and disengage the catch -64 when said springis freed from restraint by the moving-forward of the slide 3?, as willbe presently described. When thisoccurs, the,

parts assume the position shown in Fig. 3.

The rod 61 is reset to the position shown in :Fig. by the action of cam71, fixed on the.

shaft 48 and which is arranged to force the rod 61 backward by engagingfriction-wheel 72, mountedin the end of rod 61. This cam completes itsaction upon one revolution of i a the shaft 48 and by so moving the rod61 carries the dog 58 back to positionwhere it will be in the path ofthe curved arm of the clutch-controller lever 52, and thereb swing thesame back to position for uncoup ing the ing the controlling-lever 74,which is pivoted on the post 22 or other suitable support and has alateral projection 74, normally sustained on block 73. The lever 74 isconnected by a link 75 with an elbow-lever 76, provided with dependingarm 76, having a pin working in the slot in the end of link 77, whichlink is connected in' turn with bellcrank lever 78, joined by rod 79 tothe rod 69 before described. The pin-and-slot connection between link 77and arm 76 allows a certain amount of lost motion.

A spring'80, connected to the arm 76, draws the projection 74 downbehind the block 73 when the work-holding slide 3' moves forward. Whenthe projection 74,

rests on the to of the block 73, the arm 7 6 is thereby he (1 inposition shown, where, through its connection with the rod 69, it willhold the same elevated against the tendency of the spring 70 to lowersaid rod and to thereby free the catch or detent 64. As soon as,however, the arm 76 is freed by the forward movement of the slide itmoves to the right, {thereby freeing the spring 7 O and whereupon'thedetent 64 is actuated to free rod 61, and thereby connect the power tothe shaping or forging die or press. In addition to operating as'theprime controlling device in bringing the, shaping or forgin devices intooperation the projection 74 o lever 74 by dropping down behind theshoulder of the block 73 acts as a lock to hold the slide in its forwardposition during the operation of the shaping or forging die upon theheated section of the wor By this means the spreading of the work by theoperation of the die is effectually prevented. This is important,particularly in the case of butt-welding, since it eflectually overcomesany tendency of the joint to open during the action of the press or diewhen used to reduce the bur.

It will be seen that while a very small ,movement of the mechanism isrequired in order to release thecatch vor detent 64 it is neverthelessdesirable that the lever 74 should have a large movement in order thatthe lock may move down fully behind the block 73 to effectually lock thesame against rearward movement. The object of connecting said lever 74with the dog 68 through mechanism having at some point a lostmotionthus, for instance, at the point of connection between the arm 76and'77is to permit this relatively large movement to take place. Inother words, after the lever 74 has moved downward sufficiently to freethe catch 64 it may still continue its movement without moving orpermitting movement of the rod 69 and dog 68 under the action of spring70. The restoration of lever 74 and dog or latch 68 to the normalposition is eflected by means of the cam 36 on intermittently rotatingshaft 13, which cam operates for this purpose on the arm 81, extendingfrom lever 76.

- Instead of coupling the constantly running motive power to the tool wemight start the motive power which operates the tool.

60, also, instead of using mechanical control of the starting mechanismwe might use elec' 'trical controlas, for instance, by causing cated inFi 22. In this instance the cir-.

c'iit-control er (whose points are indicated at 83), might have one ofits members carried by the lever 74 and the other mounted on a suitablefixed support. In this case the arm 7 6 and the remaining mechanicalconnections between the same and the dog or latch 68 in Fig. 10 could bedispensed with. It should be mentionedthat when the lever 74 drops toposition shown .in Figs. 1, 2, and 3 it may be stopped by engagement ofthe members of the circuit-controller, or when mechanical control isemployed throughout it may be stopped by the head, which carries the dog68, reaching the limit of its downward movement and coming intoengagement with a" shoulder on the bracket 67 It will also be obviousthat the movable member of the circuit-controller 83 might be carried byother plartsas, for instance, by the slide 3 the made to temporarilymaintain position in xed memberbeing suitably mounted so as,- to beengaged by said movable member when the work softens and the slide movesforward,

as indicated'in Fig. 23. b

The circuit-controller for controlling the flow of the heating-currentin the work comprises I twoindepend entlyoperable Kbut coacting members,through which the startingcircuit is completed in series. One of saidmembers 84 is set in circuit-closing position by the" cam 35' on shaft13 and temporarily latched there until by the action of the forgingdevice the latch is tripped and the said member is allowed to breakcircuit. The other member 84 is set and maintained in circuit-closingposition by the action of cam 35 on shaft 13, which for this purpose iswhich the cam would hold the lever down. The poles of the circuit to beclosed are-connected, respectively, to the contact-springs 85 and 85,which are insulatedand are engaged, respectively, by contacts 86 and 86,

carried by the levers 84 and 84, but insulated therefrom and connectedto oneanother by wire 87. When both leversor. members 84 and 84 aredown, the starting-circuit, which,

as indicated in the diagram, Fig 20, may be pairs of saidwork-holders.

the primary circuit of the transformer, is closed, and heating-current'Wouldthen be generated in the secondary and flow through the'work,closing the gap between the two The levers 84 8.4 each have a tailpieceorarm 88, to'which is connected a spring 89, for the purpose of throwingthe leverupandbreaking the connection when the lever isfreed. Each alsohas an. upward-extending arm in its, broader aspects to produce whichthe cams on shaft 13 act to depress the levers. When lever 84 isdepressed by transient action-of cam 35 ,it is'held down by the latch91, having a heel-piece engaged by a spring 92, which tends to hold thelatch over in looking osition. The lever 84 is freed or unlatched ymeans of a .pin 93, carried by the lower end of a lever 94, which.swings upon the spindle-carrying levers 84 84. Said heel or la 91operates the same and un-' 90, upon in by engaging the upper side of thelatches the lever. The lever 94 is operated for this purpose by theforging .or shaping mechanism. 5 For this purpose we may, for instance,employ some'portion of the tool-holder or actuating devicesas,-forinstance, from the block 41, carrying the die or press 38. Said pin onthe downward movement of the tool ena pin 95., projecting from gages ashoulder or projection on an arm 96, depending from a rock-shaftcarrying an'arm 97, which is connected b a link 98 with lever'94 or'b'yother suitable means. A retractin -spring 99 is connected to an armprojecting om the arm 96. When the tool rises after doing its work,carrying the pin with it, the spring 99vrestores the pin 93 to positionwhere the latch 91 will be free to lock the lever 84 down 'when the sameis depressed. The parts of the said circuit-controller are "mounted on asuitable base 100, secured to the top of but perfectly insulated fromrapost 101, rising from the table 1.

, The -means for automatically controlling the rotation of the cam ormaster shaft 13 are shownin detail in Figs. 12, 13, 14, 17, 18, and 19.One of the special objects of these devices 'is to provide fortemporarily stopping said shaft when it reaches the position in whichthe work has been properly clamped by the action of the cams 12 12 andthe work-holding slide'or carrier 3' hasbeen released by the cam 32 andto cause such tem porar'y stop of the shaft to be maintain'ed'or delayeduntil the work is sufficiently heated. We prefer to produce the rotationof the shaft by a oontlnuousl actingv ower which uncoupled .from theshaft by means of a suitable clutch,

is intermittently coup ed to an although it would be within ourinvention the intermit'tent rotation by the starting and stopping of theprime mover. The controlling devices which we employ for securing thisaction comprise, briefly stated, a pair of cooperating detents, one ofwhich, 128', operates to hold the cdntrollingdevices imposition in whichthe cam-shaft will rotate and is released automatically by said shaftwhen it is necessary to stop the same during the heating operation,while the other member 128 acts to temporarily hold said controllingmechanism in position to permit rotation of the shaft, when saidmechanism is reset by i the operation of the press and until thecamshaft after the resumption of its rotation has permitted thefirst-named member to assume position for keeping the shaft in rotationuntil the time again comes for the shaft to automatically stop itself.

When a clutch mechanism and controlling device therefor are employed,they may be constructed as' follows:

Wheel 51, as already stated,- is continually rotated from a gear 50 onthe hub of the power-wheel and normally turns freely on a counter-shaft102, carrying at its op osite end the gear 103. When gear 51 is coup edto shaft 102 by the friction-clutch disk or wheel, the gear 103 turnsthe shaft 13 by meshing with the wheel 104 on a cam-shaft 13.Clutch-disk 106 is keyed\on shaft 102, but is capable of slidingthereon, so as to engage with or be disengaged from wheel 51. In the hubof the wheel or disk 106 is a groove in which engage the arms of thefork 108, secured to a rod 109,- upon which a spring 110 acts to forcethe members of the clutch together, in .which condition cam-shaft 13rotates. On the rod 109 is a sleeve 1 11, to which is jointed one member113 of the toggle, the other member 113 of which turns on the pin 1 14,secured to a boss rising from the casting at the back of the plates 105.

The members of the toggle are connected to a rod 115, extendinghorizontally through bearings 117 on the castings and working against aspring 118, compressed between the end of the rod and a set-screw inbracket 1 17'. the rod straightens the toggle, the sleeve 111 by actingon the nuts '112 on the end of rod .109 retracts, overcomes spring 110on said rod, and disengages the clutch, so as to bring the shaft 13 torest.

For permitting the spring 110 to bring the members of the clutch inengagement the toggle-actuating rod is retracted by means of a pin 119,which engages a shoulder 116, projecting from a sleeve 116, secured tothe rod. Said pin is carried by an arm 120, rocking on a pin 121,secured to the casting at some portion of the frame. Said arm isactuated in any suitable manner from the press or forging apparatusas,for instance, by the cam 126 on the crank-shaft 48, which op? erates theress. This cam acts on the arm 120 throug arm 125, secured to one end ofa rock-shaft 123, which is mounted in a casting on the top of theframework which carries the crank-shaft 48, and which rock-shaft has atits opposite end an arm 124, connected by link 122 to arm 120.

The pin 119 and its associated devices are maintained in the position tocouple the shaft 13 to the power and are released from such position inorder to uncouple and stop the shaft by means of the compound detentdevice before described. This detent holds when by the action of thespring 118 the arm 120 against the movement by the I sisting of twoindependently-operable pivoted detents 128 128, which are engaged by thedog or tooth 127, secured to projection 120 on arm 120. The detents areprovided, respectively, with operating-arms 129 and 129, to which are aplied suitable springs 130 and 130, normal y acting to set the detentsin position where they may hold the tooth or dog 127. The cam-shaft 13operates on the arms in the manner to cause the detents to release thedog 127 preferably in a direct manner by means of cam 37, secured tosaid shaft.

As already described, the cam or master shaft 13 carries in'all,exclusive of the detentoperating cam 37, six cams. Two of these, 12 12,(see Fig. 8,) control the operation of the clamping devices on the twowork-holders. Two others, 35 35, operate the circuitcontroller, whichestablishes and disestabllShP the flow of heating-currents through thework. A fifth cam 32 controls the action of the slide or platen 3,carrying one set of work-holding devices, and acts alternately" toretract said slide for the purpose of inserting a new piece of work andthen to free the same to permit the spring 20 or other device to bringthe two parts to be welded into contact and apply ressure thereto. Asixth cam 36 resets the ocking devices which holds the work-holdingslide during the operation of the press, hammer, or other forgingappliance and also resets that element of the mechanism which brings theforging device into op eration and which is in immediate connection withand under the control of said slide. In the present case, as already setforth, the same deviceto wit, lever 74 and its projection 7 4o erates asthe prime controlling device whic governs the actions of the hammer,press, or other forging tool and as thelocking device. ,Normally thecam-shaft 13 is rotating, since the members of the toggle 1 13 and 1 13are in the position shown in Fig. 14, being held in such position,against the force of spring 118 by the controlling dog ortooth 127 whichis detained by one of the members of the compound detent, excepting atone stage of the cycle of actions, as will be presently described.Normally the shaft 48, which operates the tool, is at rest, beinguncoupled from the power by reason of the fact that the clutch-lever 52is detained by the dog 58 in the position shown in Figs. 10 and 1 1until the work has been heated.

The general operation will be described, startlng at that stage of the,cycle of operaown when both clamping-levers are lifted by thelaction ofthe cams 12 12, so as to permit IIS theinsertion of the'work, and arejust about to free said levers by reason of the shoulder a on both camssimultaneously or approxi- Jn'ately at the same time-passing fromcon- .5tact with the rollers 14 on said levers, so as to freethe spring 11 andallow them to clamp work is now readyto-be heated and the cam 35 nowcomes into play, and its forward shoulder throws down-the member 84"ofthe circuit-controller to start the flow of heating- 15 current. 'At aprevious stage in the cycle of actions the member 84 of said circuitcontroller has beenset bythe action of thecam 35, as will be presentlydescribed, so that the 'cam when it acts will complete the. re-

2o mainin gap in the starting-circuit. Assoon' as the Q owofheating-current is established by the actionof the cam 35 the rotationof 'the cam or mastershaft 13 isinterrupted and the same remains at restto allow time for the '25 heatin ,an preferably also forthe'completion,o the orging operation; .The stopping g of the cam-shaft13 1s effectedbythe operation of the cam 37, which in the meantimehasmoved forward through the position 0 shown in Fig. 19 to the positionshown in Fig. 17', so as to remove the detent 128 and release the dog1*27. The position of the compound detent and dog shown in Fig. 19 isthe result of the action at a subsequent'stage' 3 5 of the cyclaprior,however, to thatstage or step atwhic the operation is assumed to havebegun. When the dog or tooth 127 is freed, the arm 120, carrying thesame and the pin 119, Fig. 14,:is permitted to move under 40 the actionof the spring 1 18, ,connected-to the toggle, and the latter beingstraightened so as to assume position shown in Fi 13 disconnects themembers 106 51" 0 the clutch 3', through which the power-shaft i-nipartsrotation to the cam-shaft 13. The heatin -current having been turnedinto the wor and the slide left to the action of the spring 20, the workgradually heats and softens, the

, cam-shaft 13 now being at rest, and finally the workholding slide bymoving 'forward' brings the press, die, or-other forging implement intoaction. It should be prennsed that when the shaft 13 stops thecam 36 i Ithereon is approximately in the position shown in Fig. 10, -the cams121-2in the position shown in Fig. 8, the earns 35 35 in the.

' its projection 74'" by falling behind the block '73 on the slide 3prevents the latter from-re "48, which, through the rocker-arms 1 25 124 and ting the rod 69, Fig. 10, to free and release connecting-rod 61,which thereu on removes the dog 58 from engagement wit the clutchlever52 and the latter thereupon couples the power to the crank-shaft 48, towhich the 7o tool is connected. Said shaft thereupon .the' work. As soonas'the workis'clampedcam 32'releases the slide 3 and the spring 20" v gmoves the same forward and brings the two- 10 pieces to be welded firmlyinto contact. .The'

makes a whole revolution independently of the movement of the othermechanism, brings the die into contact with the work, withdraws thesame, and finally comes to rest through 7 5' the automatic action of itscam 71, which resets the dog 58 and the connecting-rod by whose releasesaid shaft 4 8 was started,- as already explained. When the lever 74drops,

ceding ,under 7 the ex ansive efiect ofv the metal inthe holders w oncompressed by the die or tooll'f" i J ust about the time that the die ortool reaches the work the current controller is'causedto stop the fiowof current by the action of the pin 95, connected to the die, and actingthrough the rock-arms 96 and 97 and"connect-ing-rod 98 upon the latch 91to free the. ar'm84 of the compound circuit-controller. As'will be seen,the circuit is broken by this action, although the shaft 13 may stillremain'at'rest or in a position to hold the arm k or member 84' of thecurrent-controller in contact withspring 85. 5 The die-operating shaft,48 in the course of its revolution restarts the cam-shaft 13 fromtheposition in which it has been delitfid for the heating and forging 0eration. 'T 's is eflected by the cam 1 26 on s aft link122, causes thepin 119130 forc'ethe togglerod back'againto the position shown in Fig.14, thereby coupling the shaft 102 with the driving power. As the arm120, carrying the pin 119,'recedesthe-dog 127 ismoved 5 frompositionshown in Fig. 17 to position shown in Fig. 18, whereupon themember 128 of the detent springs under the dog and thereby temporarilyholds the.parts in position for maintaining the revolution. of cam-shaft13. .-When thelatter moves from its tem-.

pora ry position of rest, it finally frees the dog 128, and thelatterunder the action of the s ring moves 'into position under the 0g 127 .toreceive the same and still-maintain the partsin position necessary forrotation ofithe' shaft 13. after the said shaft with its cam 37 hascarried the detent 128 away from the stop position bypassing beyond theposition shown in Fig. 18 on its way to repeat 20 the cycle of actions.After the cam passes beyond p0sition"of engagement with the arm. 129 thedetent 128,,being slightly longer than detent 128','is prevented fromagain springing under the dog 127 by engaging theside of I 5 said dog,which at such timeis resting on the shorterdetent 128. Before passingaround to position 01 again automatically stopping itself by freeing thedetent 128 the. camshaft13performs the following operationszigo actingon the arm 81, Fig. 10, raises the lever 7 4,and immediately after thecam 32,through lever 33, presses the slide 3 back under pro- Y jection74 and maintains the slide in such position until the time comes tosurrender it to the action of the spring 20, as already described. Justbefore the cam 32 acts on the slide the cam 12 operates on theclamp-lever 10, mounted on therslide 3, so as to free the work therefromand permit the slide 3 whose clamp still grasps it to move back. As soonas the cam 32 has moved the slide 3 back as far as it will go the cam 12acts and frees the work from the clamping devices on the slide 3. ,Theclamps are now both open ready for a new piece of work, and when theoperator inserts the same the cycle of actions described is repeated;After the shaft 13'has restarted, and at anytime subsequent to the timethat it has moved forward sufficiently to free the circuit-closing lever84, but before said heating-current is again required, the cam 35 onsaid shaft 13 resets the lever 84 ready for another operation The leveris held in this position as already described by latch 91. Shouldthe-operator not place a new piece of work in the clamps before theyclose, the slides will move forward instantly without any delay incidentto the adual softening of the work, and the shaft 48 will be started sosoon that its cam 126 will have reached position to hold the dog 127 inlifted at the heating position.

position at the time thatzthe cam 37 on shaft '13 reaches position tofree said dog by operating thev detent 128. Hence the dog will not bepermitted .to drop to the position shown in Fig. 17, which it must do inorder that the toggle may be acted upon5so as to free the clutch-disk.106, and theIshaft will therefore revolve continuously and not pauseFrom the foregoing description of the op eration it will be seen thatthe master-shaft automatically stops itself, but that the restarting ofthe same is brought about by the yielding of the heated section of workto the pressure automatically applied thereto. For convenience and also.for the purpose of insuring the stoppage of the master-shaft until theforging operation is completed we prefer to include the operation of theforging mechanism in the train of actions between the yielding of thework and the restarting of the shaft.' The essential feature, however,of our invention lies in delaying the restarting of the master-shaftuntil the work has reached the desired degree of lasticity, which degreemight be different or different machines,- materials, or kinds of work.If an automatic forging operation is employed, the period of delay ispreferably exte'ndedso as to the machine a section. 1

, chine.

to the desired degree of plasticity. This,

however, is'not essential to our invention.

Inasmuch as the operations of the machine depend upon the degree ofplasticity of the -work the same machine may be successfully usedforstock of different thickness orcross- In order to permit the operatorto stop the machine at any stage of the cycle of actions, a

we provide some means for disconnecting the master or cam shaft 13 fromthe driving power, so as tobring the-same to rest. This is convenientlyaccomplished by providing an additional yoke 108, engaging a groove inthe hub of the clutch-disk 106 and operating' the same to holdtheclutch-disk back 8 against the action of the spring 1 10 by means i of arocker-cam or eccentric 131, which is adapted to engage a shoulder 132,secured to a rod 133. carryingthe yoke 108'. v Said cam is rocked by.means of a rod 134, attached to an arm 135 of a rocker, another arm 136of which is joined by rod 137 with a treadle 138.

A sprin 139, Fig. 2, attached at one end to the tab e 1, its other endbeing fastened to the arm 135, serves to normally keep the rocker-cam oreccentric 131 out of engagement with the shoulder 132. A sleeve .142slides on the cross-bar 140 of the frame 2'and carries a rojection 141,which serves to lock the trea e when it is desired to stpp the ma Fig.16 illustrates a modification in the form of the upper die or tool 38,whereby the bur incident to welding the two pieces of metal together canbe removed at the time I of forming the weld.

We claim as our invention- 1. In an electric metal-Workin apparatus, thecombination of a work-hol er, a spring for applying spring-pressure toupset the 05 heate section of work and a counteractingspring acting onthe holder to oppose the ac tlon of the first-named spring during theforward movement of the holder as the WOIk softens.

2. In an electric metal-workin apparatus, the combination of a work-holer operated by spring-pressure during the upsetting of the softenedmetaland means for'exerting an opposing action to said spring-pressureincreas 1 I 5 mg in amount with the movement of the parts in suchupsetting operation.

3. The combination in an electric metalworklng apparatus, of a clampindevice, a suitable slide or-block carrying t e same, 8.1 12 springofsufficient power to apply the weldmg or upsetting pressure to thework, means disconnected from the slide for putting said spring undercompression, and. a counteract-' v lug-spring ofless-poweractin tooppose the 12 5 spring-pressure exerted by sue. first-named spring andthereb prevent too sudden ac:

tlon when the wor hecomes fully softened.

4. an electric metal-working apparatus, I the combination of a springfor applying a determinate upsetting pressure to the work and means forapplying a, counteracting force of increasing amount as the worksoftens.

. 5. In an electric metal-working apparatus, the combination of meansfor applying an upsetting spring-pressure to the work and means forretarding the action; of said spring as the work softens. i I

6. In an electric metal-working apparatus the combination with a worl-holder of means for forcing it toward the opposite workholder, a.counteractin'g-spring'and an-intercombination of a spring for applyingpressure to the heated section of-work, mechanism for 4 -motion of tmediate lever having an adjustable fulcrum. 7. In an electricmetal-working apparatus the combination with means of a plymg weldingpressure to the heated wor of a "counteracting-spring and a lever.through which the counteracting effect of said spring ,is transmittedand meansfor changing the position ofthe fulcrum of said lever to varythe counteractingeffect.

8. In an electric metal-working apparatus the combination with a blockfor applying welding pressure to the work, of means for forcing theblock forward to affect the work,

a cam for alternately retracting the block and freeing the same when thewelding pressure is to be ap lied and means for retarding the lie blockas it moves forward.

1 9. In an electric metal-working apparatus the combination of areciprocating block through which pressure is applied to the heatedsection of the work, a spring acting thereon to move it forward, a camfor alternately forcing the block backward and releasing it to theaction of the spring and a counteracting-spring connected to the blockfor retardmg the forward motion ofthesame.

10. In an electric welding apparatus .the

releasing said spring to permit it to act and a counteracting-spring asand for the purpose described.

11. In an electric metal-working apparatus the combination with aspring-actuated work-holder, of means for applying a counter-, actingforce when the work-holder moves fore ward to compress the heatedsection of .work

an :1 a lever having an adjustable fulcrumfor varying the counteractingforce.

. '12. In an electric metal-working apparatus, the combination with aclamp-supporting block and a forging-tool, of an actuating mechanismtherefor, a couplin for connecting the tool and actuating mechanism, adog by which the members of the cou ling are held disengaged and acontrolling-ever for said (leg normally restrained by the block.

13. In an electric metal-Working apparatus, the combination with aclamp-supporting block, of a for ing-tool, a spring-actuated rockingcoupling ey or pin, a dog normally released when, the work softensholding the same out of action and means connected with theclamp-supportingblock for releasing the dog and thereby coupling theforging-tool to the operatingpower when the block is permitted tomoveforward by the softening of thework. I

14. In an electric metal-workin apparatus, the combination with, the wor-holding carrier of an automatic lock for locking the same in itsforward position during the forging of the heated Work.

15. In anelectric metal-working a para? tus, the combination of aforging or s apin'g' mechanism, a work-holding carrier, a lock forlocking the same in its forward position during the shaping or forging,means connected with said lock for bringing the forging or shapingmechanism into operation when the carrier moves forward, and acontrollinglever connected with the releasing mechanism and normallyrestrained by engagement with the work-holding carrier. 7

16. In an electric metal-workin apparatus, the combination of'a workholing slide, a-toolactuating shaft, a clutch coupling the same to apower-Wheel, a dog normally en-. gaging the clutch-'operating-arm andholding the same uncoupled,- acatch controlling the action by thework-ho1din slide, but released thereby" when th.e softening of the workpermits the slide to move forward, and, means connected with thetool-actuating anism to normal position.

mechanism for restoring said releasing mech 18. In an electricmetal-working apparatus, the combination with the tool-shaft of acoupleradapted to connect the same to the power device,.a dog fornormally holdin said coupler in uncoupled position a work-ho ding Islide, means controlled thereby for actuating the dog to free thecoupler device, and means connected with the tool-shaft for restoring vthe do to normal position.

19. n an electric metal-working apparatus, the combination with thetool-shaft of a coupler adapted to connect the same to the power device,a dog for normally holding said coupler in uncoupled position, means forapplying pressure to an electrically-heated-section of metal, meanscontrolle thereby for actuating the dog to free the coupler device,

and means connected with the tool-shaft for V restoring the dog tonormal position.

20. In an electric metal-working apparatus, the combination of atool-actuating shaft 5'or mechanism, a clutch-controlling arm, a

dog normally restraining the same in un coupling position, awork-holding slide, an arm normally sustained thereby but released whenthe slide moves forward, means con- IO trolled by said arm for governingthe position of the dog to \release the clutch-controlling arm, andmeans connected with the tool-actuating devices for restoring the dog toposition for uncoupling the tool from the power.

shaft for starting the flow of heating-current in the work and meanscontrolled through-i the yielding of the work under pressure forrestarting said master-shaft and cutting off the flow ofheating-current.

22. In an electric metal-working apparatus, the combination of awork-holding slide,

means for applying pressure to the heated sec-' tionof the work, acam-shaft provided with a cam controlling thegapplication of theressure, means connected to said cam-sha t for 5 starting the flow ofheating-current in the 1 'wvork, means for automatically bringing the-cam-shaft to rest as soon as pressure and heating-current are appliedto the work, a forgin apparatus normally uiescent, means 40 contrcfiledby the yielding o the work under ,pressure when brought to plasticcondition I for starting the forging apparatus, a clutch by which thecam-shaft is coupled to its power-shaft and means carried by the forg- 5ing apparatus for'actuating said clutch to ring its members intoengagement and restarting the cam-shaft. Y

23. The combination, in an electric metal- Working apparatus, of aWork-holding slide,

means for applying pressure thereto and through the same to the heatedsection of the work, a startingswitch for starting the flotv ofheating-current, a forging-tool, normally uncoupled from a suitablepower, means for coupling the same automatically to the power when theslide moves forward through the softening of the work, a master-shaftnormally coupled to such power and cams thereon acting respectively tostart the flow of 6o current, 1elease the pressure devices, andautomatically stop the master-shaft by uncoupling the power, and meanscontrolled by the actuating devices of the die or forging-tool forautomatically recoupling the cam-shaft tus, the combination of awork-holder, a forgto the power whereby the same may be re- 6 5'started.

24. The combination, in an electric metalworking apparatus, of awork-holding slide, means for applying pressure thereto and. through thesame to the heated section of the work, a starting-switch for startingthe flow of heating-current, a forging-tool normally uncoupled from asuitable power, means for coupling the same automatically to the powerwhen the slide moves forward through the softening of the work, amaster-shaft, a clutch by which the same is normally coupled to suchpower, a detent holding the clutch members in en agement, a cam on themaster-shaft for reIeasing the detent, a cam on said shaft for startingthe flow of heatingcurrent and a cam on said shaft for controlling theapplication of pressure to the work.

25. In an electric metal-working apparatus, the combination of .aspring-actuated work-holder, a forging-tool, a coupling de- -vice forcoupling said forging-tool to a suitable power, means controlled by theworkholder for bringing the coupling device into operation, acircuit-controller governing the flow of heating-current in the Work, amastershaft, a clutch by which the same is normally connected to thedriving power, means on said shaft for actuating or controlling thecircuit-controller, means connected with said shaft for automaticallyuncoupling it from the driving power whenthe flow of heating-current hasbeen established by the circuit-controller and means connected with theforging-tool for automatically recoupling said master-shaft with itsoperating parts.

26. In an electric metal-working apparatus, the combination of awork-holder, a forging-tool, mechanism controlled by the work-holder forbringing the forging-tool into operation when the work softens, anormally rotating mastershaf t, means controlled thereby for startingthe flow of heatingcurrent, means for automatically stopping saidmaster-shaft when the flow of heating-currentis established, and meanscontrolled by the forging-tool for restarting the mastershaft.

27. In an electric metal-working appara- I l D ing-tool, mechanismcontrolled by the workholder for bringing the forging-tool intooperation when the work softens, a normally rotating mastershaft, meanscontrolled thereby for starting the flow of 'heating-cur- 12o rent andclamping the work, means for automatic'ally stopping said master-shaftwhen the flow of heating-current is established, and means controlled bythe forging-tool for restarting the master-shaft. 1 2 3 28. In anelectric metal-workingapparatus, the combination of awork-holder, aforgmg-tool, mechanism 'controlledby the workholder for bringing theforging-tool into operation when the work softens, a normally rotatingmaster-shaft, means controlled thereby for starting the flow ofheating-curslide of a forging-tool, means for bringing the sameinto'operation when the slide moves forward through the softening of thework, ,a master-shaft provided withmeans for automatically clamping thework and releasing the slide, means for automatically stoppin said shaftin position to clamp the work an means controlled by the forging-toolfor restarting the master-shaft.

30. In an electric metal-working apparatus, the co'mbination'of amaster-shaft provided with means for controlling the flow of theheating-current, stop mechanism for automatically stopping said shaft, atool o erating shaft, means controlled by the yiel ing of the heatedsection of work for starting said shaft and a cam thereon for'resettingsaid stop mechanism in order to restart the. master-shaft.

31. In an electric metal-working apparatus, the combination of amaster-shaft pro.- vided with means for operating the clamp devices,stop mechanism for automatically stopping said shaft, a tool operatingshaft, means controlled by the yielding of the heated section of workfor starting said shaft and a cam thereon for resetting said stopmechanism in order to restart the master-shaft.

32. In an 'electric metal-working apparatus, the combination with amaster-shaft provided with means for controlling the flow ofheating-current, of a clutch, a spring-actuated toggle for disconnectingthe members of the clutch, a detent normally holding said spring out ofaction and means connected to said shaft for operating the detent whenthe shaft reaches position for establishing the flow of heating-current.

33. In an electric metal-working apparatus, the combination with amaster-shaft provided with means for controlling the flow ofheating-current, of a-clutch, a spring-actuated toggle for disconnectingthe members of the clutch, a detent normally holding said spring out ofaction, means connected to said -work yields to pressure.

34. In an electric metal-working apparatus, the combination with amaster-shaft provided with means for controlling the flow ofheating-current, of a clutch, a spring-actuated'toggle for disconnectingthe members of I the clutch, a detent normally holding said spring outof action, means connected to said shaft for operating the detent whenthe shaft 'reaches position for establishing the flow of heating-currentand mechanism controlledby the work-holding slide or carrier forrestoring the toggle and clutch to position for rotating the shaft.

35. 1n an electric metal-working apparatus, the combination with amaster-shaft pro- I vided'with ineans'for controlling the flow ofheating-current, of a clutch, a spring-actuated'toggle for disconnectingthe members of the clutch, a detent normally holding said spring out ofaction, means connected to said shaft for operating the detent when theshaft reaches position for establishing the flow of heating-current, aforging-tool, means controlled by the yielding of the heated section ofwork for bringing the tool into operation and mechanism connected withthe tool-operating devices for-restoring the toggle and clutch toposition for rotating the shaft.

36. The combination in an electric working apparatus of a Work-holdingcarrier, an automatic lock for locking the same in its forward position,a forging-tool and actuating devices controlled by the carrier and meanscontrolled by the operating mechanism of a forging-tool for unlockingthe carrier.v

37. The combination inan electric working apparatus of a power-actuatedforging-tool, a work-holding carrier, means controlled thereby forcoupling forging-tool to-its actuating power, means for locking thecarrier in the position to which it is permitted'to move by thesoftening of the work and means connected with the forging-tool forunlocking said carrier. I

38. In an electric metal-Working-apparatus, the combination of amaster-shaft and circuit-controller actuated thereby, a springactuatedclutch by which said shaft is normally coupled to the driving power,mechanism acting against said spring to throw the members of the clutchout of connection, de- I tent devices normally holding said mechanismout of action, means connected with the shaft for actuatingsaid detentdevices and releasing said mechanism when the shaft reaches position forestablishing the flow of heating-current and means controlled by theyielding of the heated section of work for returning the detent devicesand the mechanism'controlled thereby to normal position.

39. In an electric metal-working a paratus, the combination of amaster-sha t' and circuit-controller actuated thereby, a springactuatedclutch by which said shaft is normally coupled to the driving power,mechanism acting a ainst said spring to throw the members of t e clutchout of connection, detent devices normally holding said mechanism out ofaction, means connected with the shaft for actuating said detent devicesand releasing said mechanism when the shaft reaches position forestablishing the flow of heatin -current, a forging-tool controlled bythe yie ding of the heated section of work and means connected with saidfor ing-tool for returning the detent devices an mechanism controlledtherebyto position in which the shaft and the driving power are coupled.

40. In an electric metal-working apparatus, the combination with themaster-shaft and means actuated thereby for controlling the flow ofheating-current of a pair of coop- 1 erating power controlling detents,means connected with shaft for operatin said detents to bring the shaftto rest and means operated independentl of the shaft for setting theother one of sai detents in position for keeping the power temporarilyin operation after the shaft resumes its rotation.

41. In an electric metal-working apparatus, the combination with thepower-shaft and means controlled thereby for establish' ing thefiow ofheating-current, of a detent actuated by the shaft, mechanism controlledby said detent for stopping the rotation thereof, means for restoringsaid mechanism to position for restarting the shaft and a secondtemporarily-acting detent for holding said mechanism in position afterthe shaft resumes rotation.

42. In an electric metal-Working apparatus, the combination with thepower-shaft and means controlled thereby for establishing the flow ofheating-current, of a detent actuated by the shaft mechanism controlledby said detent for stopping the rotation thereof, means for restoringsaid mechanism to position for restarting the shaft, a secondtemporarily-acting detent for holding said mechanism in position afterthe shaft resumes rotation, and means connected with the shaft forreleasing the latter detent and thereby deliverin the control of thestartingand stopping mec anism to the first-named detent therebypreparing the apparatus for a repetition of the automatic stoppingarrangement.

43. In an electric metal-working apparatus, the combination with amaster-shaft of mechanism for stopping and starting the rotationthereof, a pair of spring-actuated detents for holding said mechanism inposition to produce rotation, means on the shaft acting on one of saiddetents to release the mechanism and stop rotation of the shaft and uponthe other detent to deliver the mechanism to the control of thefirst-named detent.

44. In an electric metal-workingapparatus, the combination with themaster-shaft and the power-controlling mechanism by WhlCh the same isrotated, of a pair of detents one of- 128 and 128 of different lengths,a dog connected to the controlling mechanism and adapted to engageeither of said detents and means connected with the shaft for acting onsaid detents at different stages of the revolution of said shaft.

45. In an electric metal-working apparatus, the combination with themaster-shaft of the spring-actuated detents 128, 128 of differentlengths, a dog 127 detained thereby and connected with mechanism forstarting and stopping rotation of the shaft, a cam carried by said shaftand acting on said detents, means controlled by the shaft for startingthe flow ofheating-current and means responsive to the yielding of thework when rendered plastic by the heating for returning the dog 127,from position assumed when it has been freed by both detents.

46. The combination with an electric metal working apparatus of acurrent-controller having two members which coact to close the circuit,a cam for holding one of said members in circuit-closing position whileheatin current is required, a latch or catch for holr ing the other'member in circuit-closing position and mechanism for depressin saidmember and throwingit into circuit-c osing position in the intervalbetween the periods of use of the heating-current.

47. In an electric metal-working appara tus acurrentcontrollerhaving'two members which coact to close the circuit, a latch for holdingone member in closed position, a cam acting momentarily on said memberto throw it into circuit-closing position and a second cam for holdingthe other member incircuitclosing position. I

48. In, an electric metal-working apparatus, a current-controller havingtwo members which coact to close the circuit, a latch for holding onemember in closed position, a cam acting momentarily on said member tothrow it into circuit-closing position, a- -second cam for holding theother member in circuit-closing position during the time that theheatingcurrent is required and means for acting on said latch to freethe member held thereby in order to stop the-flow of current.

49. In'an electric metal-working apparatus, a current-controller havingtwo members which coact to close the circuit, a latch for holding onemember in closed position, a cam acting momentarily on said member tothrow it into circuit-closing position, a second cam for holding theother member in circuit-closing position during the time that theheatingcurrent is required, mechanism for forging or shaping thh'eatedsection of work and means connected therewith for operating on saidlatch to free the member locked thereby and thereby stop the flow ofheating-current.

50. In an electric metal-Working apparatus, the combination with acircuit-controller, having two members which coact to cause a

